Maria Anna, who had a particular fondness for hunting, received a strict Jesuit upbringing[2] and was considered a great beauty with exceptional virtues, such as prudence, orderly life and stateliness.

On 15 July 1635 at the Augustinian Church, Vienna, Maria Anna married her uncle, Maximilian I, Elector of Bavaria, whose previous wife, Elisabeth of Lorraine, had died a few months earlier.

With this union, the Bavarian elector not only gained the opportunity to sire the long-waited heir (his first marriage was childless) but also to demonstrate his alliance with the Holy Roman Empire against France, which was prepared for an imminent war.

Maria Anna assisted her husband in government affairs and showed interest in the politics of the Bavarian electorate; she even took part in the meetings of the Council of Ministers.

After the conquest of Philipsburg fortress by the French in 1644, Maria Anna urged her brother Leopold Wilhelm, on behalf of her husband, to enter into peace negotiations.

Thus, after Maximilian I's death (27 September 1651) his brother Albert VI, Duke of Bavaria legally became the regent for Ferdinand Maria and was confirmed in that position in both Imperial and electoral courts.

Maria Anna assumed full responsibility for the Department of Justice and other country administrative tasks, however, which virtually left the Dowager Electress ruler of Bavaria.